The Coast Guard Academy, which is involved in the most comprehensive concussion study to date, is preparing to track cadets after they leave the academy to examine the impact a concussion can have on a person's brain over time.

The study, launched in 2014 by the NCAA and the Department of Defense, initially looked at the impacts from concussions or repeated head injuries in the hours, days and weeks after the injury, and compared those to assessments done beforehand. Now, it is expanding the study to look at potential cumulative effects.

SEATTLE — The icebreaker Polar Star was 1,000 miles out of its home port of Seattle last December, three days into its yearly voyage to resupply scientific bases in Antarctica, when a powerful swell hit its bow and flooded the deck.

The ship shuddered.

The roar of the ventilators in the galley quit as Joseph Sellar, a stocky 25-year-old Coast Guard culinary specialist from New Hampshire, watched seawater explode from the ceiling.

He lunged toward a switch to close the overhead vents. With a loud pop, an outlet ejected a purple spark.

"Are we sinking?" asked a petty officer on temp duty from Virginia.

Sellar knew better.

"Calm down," he said, whipping out his cellphone to record the gusher.

The United States spends $2 billion a day on the most advanced military ever assembled, with more aircraft carriers, fighter planes and nuclear submarines than any other nation. The Pentagon intends to develop a space fleet of orbiting lasers, missile sensors and satellites.

In July, yet-to-be-commissioned Coast Guard cutter Midgett passed through the Panama Canal and started a roughly 5,000-mile trip to Honolulu.

The Coast Guard accepted the Midgett in April, and it didn't leave the Mississippi shipyard where it was built until June 11. But the newest national-security cutter was ready as it transited the eastern Pacific, and with good reason — the ship helped intercept more than 2,100 pounds of cocaine before it even made it to its home port.